Composites Based on Polyethylene and Keratin Hydrolysates

Novel composites based on polyethylene ELITE™ 5230GC and keratin hydrolysates (amino acid composition, dipeptide, tetrapeptide) have been first developed and studied. It has been shown that the introduction of keratin hydrolysates leads to an increase in the elastic modulus E0 of the composites compared with the E0 value of the matrix and a decrease in their tensile strength and elongation at break. It has been found that the water content in keratin hydrolysates is 3–4%. The differential scanning calorimetry curves of keratin hydrolysates exhibit a broad peak during the first heating and no peaks during the second heating of keratin hydrolysates. The temperature corresponding to the minimum of the broad peak observed during the first heating is shifted to low temperatures: from 99.1 to 82.5°C. In this case, the peak area varies from 109.3 J/g for the amino acid composition and 104.0 J/g for dipeptide to 140.8 J/g for tetrapeptide. During the second heating, the peak temperatures for the composites decrease compared with the peak temperature for polyethylene. The enthalpy of the composites also decreases compared with the enthalpy of the matrix.